Volvo Penta Kad42p & 290dp

[Sea Runner]

Earlier this year after taking the boat out for a spin all seemed good till we got back to our berth. The port engine seemed to be making a knocking sound but it was running fine and starts straight away every time. So I got a chap in to take a look for me and he said it was coming from cylinder 6. When he cracked the injector the noise stopped so he swapped around the injectors but the noise stayed with no 6. Well I've now had the engine lifted out and sent off to be checked over but this is the puzzling bit. They ran it up in the workshop and it's purring like a kitten with no knocking what so ever. They invited me down to listen for myself. They checked all the valves and rockers etc and tested all injectors but can't find anything wrong.

What they have not done is drop the sump to look at the bearings but they are saying it really is unlikely to be the bearings on an engine that has only 1000hrs on the clock and to them its running fine, so why waste money.

I'm now thinking about the 290dp and maybe in the boat it was vibrating against something.

I just don't know really what to do so I'm now at the point of putting it back in the boat and hoping for the best.

If anyone on here has experienced or heard of this before then by all means reply as any thoughts would be welcome.

 

[Sea Runner]

Moderator, Sorry for some reason this has posted twice. Please delete this one.

 

[baylabayla3288]

Swap the drives and se what happends, i realize this might be difficult if you have taken one engine out allready. Could it be the injection pump? I had a similar issue with a knocking sound on a kad 42 that became very noticable when the engine was warm and it was the injector in the end.

 

[Sea Runner]

Thanks Baylabayla, I am starting to think about sending the injection pump off for testing and maybe reconditioning. At the moment I'm just running it as it's now the summer season and what happens, happens.